Self-aligning mechanism for regulating the discharge of solids from a centrifuge



Oct. 26, 1965 L. THOMPSON 3,213,879

SELF-ALIGNING MECHANISM FOR REGULATING THE DISCHARGE OF SOLIDS FROM A CENTRIFUGE Filed Aug. 25. 1961 IN V EN TOR. LEE Lin EH5 THUMPSfl/V United States Patent 3,213,879 SELF ALIGNING MECHANISM FOR REGU- LATING THE DISCHARGE 0F SOLIDS FROM A CENTRIFUGE Lee Lavere Thompson, P.O. Box 547, Iowa Park, Tex. Filed Aug. 23, 1961, Ser. No. 133,388 1 Claim. (Cl. 137-5214) This invention relates to improvements in an orifice regulator for centrifuge machines and particularly an orifice regulator for centrifuge machines which separate solids from liquids, such as separating sand from drilling mud in the drilling of wells.

This invention is an improvement over the mechanism for regulating discharge from an orifice as disclosed in prior application, Ser. No. 109,458, filed May 1, 1961 by Lee Lavere Thompson and Joel A. Cathey, and now abandoned.

The present regulator element is self-aligning with the seat on the discharge opening of a centrifuge machine so as to enable the closing of the discharge opening therein to prevent air from being sucked into the centrifuge and to open said discharge opening sufficiently to enable the discharge of sand and other dense solids therefrom.

The present invention relates particularly to the feature of aligning the seating element with the seat in such manner that a complete seating seal is had around the entire circumference of the discharge opening.

As set forth in the co-pending application, it is desirable to separate solids from liquids in the drilling of deep wells by the rotary drilling method, wherein a mud of relatively high viscosity and weight is pumped into a bore hole of a well through a conduit to the bottom of the well and returned to the surface to bring the earth cuttings to the surface of the well being drilled. These cuttings include sand, shale, rock cuttings, and gravel, which must be separated from the mud, so that the solids may be disposed of, and the mud, which has been cleansed of the solids, may be reused.

The material from which the so-called drilling mud is made is composed of bentonite clays, weight increasing material such as barites and the like, and another material is also sometimes used, which is known as lost circulation material, and may be cottonseed hulls and other bulk or fibrous material. The mud for each invidual well is preferably compounded to meet the needs and conditions of that particular well and great engineering skill is required to prepare the drilling mud best suited for the particular formation. Since the cost of the mud is relatively high, it is desirable to keep the loss of the mud to a minimum; however it is also very important that the solids be removed from the mud, so as not to be recirculated into the well. One of the most damaging solids which can be recirculated is sand. Because of the qualities of sand, the drilling machinery will be rapidly abraded, particularly drill pipe, drill bits, and casing, and it is to this end that the present invention has been designed.

An object of this invention is to provide an orifice regulator for a centrifuge desanding device which will permit full fiow of solids, either fine or coarse, or which will pass a minimum quality of solids with a minimum loss of drilling fluid.

Another object of the invention is to provide an orifice regulator for centrifuge desanding devices or the like, which will discharge solids, but which will retain lost circulation material within the mud in which it is suspended.

Still a further object of the invention is to provide an orifice regulator for a centrifuge device which will seat 3,213,879 Patented Oct. 26, 1965 in sealing relation around the entire circumference of a discharge orifice.

And still a further object of the invention is to provide an orifice regulator for discharging solids from a centrifuge desanding device which is low in cost of manufacture, easy to use and to regulate, and which efficient- 1y separates solids from liquids.

A final object of this invention is to pI'OVide an orifice regulator member for the solids discharge opening of a centrifuge which is self-aligning.

With these objects in view and others which will become manifest as the description proceeds, reference is to be had to the accompanying drawing in which like reference characters designate like parts in the several views thereof, in which:

FIG. 1 is a fragmentary, longitudinal, sectional view through the lower end portion of a centrifuge desanding device, showing the present device installed thereon, with parts being shown in elevation and with other parts being broken away or shown in section to bring out the details of construction;

FIG. 2 is an enlarged bottom plan view of the seating element removed from the centrifuge desanding device and showing parts thereof as being broken away;

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2, looking in the direction indicated by the arrows, and showing the maximum limits of universal movement of the seating element with respect to the mounting element in dashed outline;

FIG. 4 is a view similar to FIG. 1, but showing a modified form of the device in closed position against the lower end of a centrifuge desanding device; and

FIG. 5 is an enlarged elevational view of the orifice closing member as shown in FIG. 4, showing parts thereof as being broken away and in section to bring out the details of construction.

With more specific reference to the drawing the numeral 6 designates generally a centrifuge desanding device such as described more specifically in the above mentioned application for patent, and which is used in conjunction with a mud pump to pump the drilling mud containing sand, shale, gravel, rock cuttings, and the like from the well being drilled with the mud from which the solids have been separated passing upward and out through a discharge at the upper end thereof, with the solids being discharged through a discharge opening 8 in the lower end thereof. The centrifuge desanding device 6 is usually composed of an outer metallic shell 10 and an inner-liner 12 which has a neck 14 on the lower end thereof which forms a seat on which a universally mounted valve seat 16 is adapted to seat.

The seat 16, in the form of the invention as shown in FIGS. 1 through 3, has a ball 18 on which an outwardly extending stem 20 is secured. A metallic, conical valve member 22 has a rounded apical surface 24 which is complementary to the ball 18. A ball retaining shell 26 is secured to the concave side of the cone 22 with the ball 18 in place, as shown in FIGS. 2 and 3. The shell 26 has an opening 28 therein which is sufiiciently large that the screwthreaded stem 20 on ball 18 may swing from side to side, as indicated by lines a and b in FIG. 3, to enable the elastomer, conical covering 30 which is bonded to member 22 of valve 16 to align in seated relation with the periphery of opening 8.

The conical metal shell 22 has holes 23 drilled circumferentially therearound a spaced distance inward from the periphery thereof to perform the bonding seal therewith. The elastomer covering 30 is pressed through holes 23 to form outwardly extending mushroomed anchor members 31 to securely hold the covering 31 in place on the surface of metal, conical member 22. The plate 26 is spot welded or otherwise secured to conical metal member 22 in a manner well known in the art of metals.

The covering 30 is made of an elastomer material, such as rubber, or synthetic rubber, so it will form a tight seal with the periphery of opening 8 in the lower end of centrifuge 6. The stem 20 is screwthreaded, as indicated at 32, and a nut 34 is adapted to threadably engage the threads 32 of screwthreaded member 20, which screwthreads also engage the threaded end of pivoted U-shaped member 36. The U-shaped member 36 is pivoted by a pivot pin 38v to lugs 39 on the lower end of shell 10 so as to swing from the full outline to the dashed outline position as indicated in FIG. 1 in accordance with the weight of the solids on the upper face of conical covering 30.

An outwardly extending arm 40 is threadably connected to U-shaped member 36, which arm has a weight 42 thereon to regulate the pressure exerted against the lower peripheral seating face on the lower end of neck 14, so as to seal the discharge opening 8 of the centrifuge.

The valve seating elements, such as disclosed in the above co-pending application must be adjusted to seat in perfect relation with the lower end of the centrifuge opening to obtain the desired results, and should the stem, on which the valve member is secured, become bent or distorted the seal will be lost and since a partial vacuum is created within the centrifuge, air will be admitted thereinto, and with the air breaking the vacuum seal drilling fluid will be lost through the discharge opening thereof. However, the above mentioned valve seat will give excellent performance under well adjusted and well controlled tolerances. The present device, however, does not require such close fitting tolerances, as the cone 16 is selfcentering and should one side become worn more rapidly than the other, a movement between the ball 18 and the complementary seating surface 24 will be had to enable the seating of the elastomer surface 30 on the lower end of the rubber neck 14 to prevent entrance of air into the chamber of the centrifuge and the loss of liquid drilling mud therefrom, yet permitting the discharge of solids as the solids accumulate on the upper surface of the conical, elastomer member 30, to such an extent that the solids, such as sand and the like, will discharge outward therefrom, yet maintaining the drilling fluid and lighter solids, such as lost circulation material, therein.

Modified form of the invention A modified form of valve seating arrangement is shown in FIGS. 4 and 5, wherein the valve seating member 51 preferably is of a molded elastomer such as rubber or synthetic rubber, and preferably has a conical upper face 52 with a downwardly extending neck portion 54, which neck portion 54 is adapted to receive a coiled spring 56 therearound. The coiled spring 56 may be frictioned onto the neck 54 at one end to securely hold the valve member 51 thereon. The other end of the coil spring 56 may be screwthreaded onto' a threaded stem 58 and the screwthreaded portion 60 of stem 58 has a nut 62 thereon which is screwthreaded into the U-shaped member 36 in a manner set out above. The nuts 34 and 62 serve in the capacity of lock nuts, so when the respective screwthreaded members 20 and 58 are in proper adjusted relation the nuts may be locked so as to hold the valve members in fixed relation thereto.

The coiled spring 56 permits lateral swinging action of valve member 51 so upon pivoting of U-shaped member 36 about pivot pin 38 the spring 56 will compensate for a slight misalignment or for wear of either the valve 51 or the valve seat on the lower endof neck 14, around the periphery of hole 8. Therefore, a fluid tight seal may be had at all times desired. Upon solids accumulating on the upper face 52 of valve member 51, the solids will work out through opening 8 between the valve member 51 and the peripheral seating edges thereof so as to permit ready discharge of the solids, yetmaintain the drilling mud therein and also prevent the entrance of air into the centrifuge chamber. The operation of the present form of U-shaped member 36, arm 40, and control ball weight 42 is substantially the same as the copending application above mentioned, and as the form of the invention set out above.

The arm 40 has a bore 40a formed transversely therethrough to receive pivot pin 38, which pivot pin extends through holes in apertured lugs 39. A side of the arm 40 is slitted on the lower side thereof in such manner as to be in communication with the bore 40a. The slitting of the arm 40 in this manner lessens the friction on pin 38 and at the same time provides an opening through which dirt, contamination, and mud may work out or drain therefrom, thereby enabling the arm to freely pivot about pin 38 at all times.

Having thus clearly shown and described the invention, What is claimed as new and desired to be secured by Letters Patent is:

A regulating mechanism for regulating the discharge of solids from a centrifuge having a substantially upright,

conical housing, the walls of which housing extend downwardly and inwardly, which housing has a discharge opening formed in the lower end thereof, said regulating mechanism comprising a counterweighted arm pivotally mounted on said housing near the lower end thereof, a

pressure actuated, self-aligning valve member secured to an end of said arm and being adapted to close said opening in said centrifuge when said valve member is in one position, a ball attachably connected to said pivoted arm adjacent the discharge opening in said housing, a metallic,

conical valve member having the apex thereof partispherical in shape and being complementally seated on said ball, with the lower edge of said metallic, conical valve member depending below the center of said ball, a ball retaining shell surrounding said ball and being secured to the concave side of said metallic, conical valve member, an elastomer, imperforate covering bonded to the exterior face of said metallic, conical valve member, which valve member is responsive to positive and negative pressures within said housing to discharge solids from the opening in the lower end of said housing when the positive pressure on the upper face of said valve member exceeds the negative pressure in the chamber of said centrifuge.

References Cited by the Examiner I REUBEN FRIEDMAN, Primary Examiner.

HARRY B. THORNTON, HERBERT L. MARTIN,

. Examiners. 

